Addressing a joint session of Congress on Wednesday night, President Barack Obama laid down the gauntlet for House and Senate members to move quickly and decisively on his proposals for health-care reform legislation.

"The time for bickering is over," the president told members of Congress in the nationally televised speech. "The time for games has passed. Now is the season for action."

Though he originally hoped to have some form of health-care reform passed by August, the president's efforts were hampered by infighting among Republican and Democratic legislators prior to Congress' summer recess, the spectacle of some angry voters shouting down those legislators at town-hall meetings last month and what he described as "scare tactics" by opponents.

Despite providing just a few more details about how his plan would work during the 47-minute speech, Obama sternly warned that he would not waste time arguing with his political opponents, "who have made the calculation that it's better politics to kill this plan than improve it." He also dismissed some of their more outrageous claims, such as those of so-called "death panels" that would withhold care to elderly citizens with terminal diseases. "It is a lie, plain and simple," Obama said.

Another denial of rumors that Democrats were proposing health coverage for illegal immigrants provided one of the most dramatic moments in the address: In a breach of decorum, Republican Representative Joe Wilson of South Carolina yelled repeatedly, "You lie!" Wilson later apologized to the White House for his outburst.

"I will not stand by while the special interests use the same old tactics to keep things exactly the way they are," Obama said. "If you misrepresent what's in the plan, we will call you out. And I will not accept the status quo as a solution. Not this time. Not now."

Looking to quell some of the controversy stirred up by the much-televised heckling at this summer's town halls, Obama explained that under his plan all Americans would be legally required to have health insurance, comparing it to the mandatory car insurance in most states. He also said businesses would be required either to offer health-care coverage to workers or to help cover employees' costs of buying coverage.

A big part of Obama's plan has been the so-called "public option," a proposal for a government-run, not-for-profit public health insurance program, which he said would force private health insurance companies to lower prices to compete. In Wednesday night's speech, in another sign that the White House may be willing to back down a bit on that part of the plan, which Republicans unanimously oppose, the president referred to the public option as one possible alternative for increasing competition for health insurance, suggesting that he was open to other ideas.

"I will not back down on the basic principle that if Americans can't find affordable coverage, we will provide you with a choice," he added forcefully. "And I will make sure that no government bureaucrat or insurance company bureaucrat gets between you and the care that you need." Obama also tried to allay Republican fears that the public option would cripple private insurers and lead to a government takeover of health insurance.

"Let me be clear: It would only be an option for those who don't have insurance," he explained. "No one would be forced to choose it, and it would not impact those of you who already have insurance. In fact, based on Congressional Budget Office estimates, we believe that less than 5 percent of Americans would sign up."

The speech also sought to head off other fears that the plan would increase the federal deficit — with Obama repeating that the savings in the current health-care system would cover the costs of the bill — and to reassure the elderly that cost cutting in Medicare would not impact their current services. Trying to put the plan in perspective, Obama said its $900 billion over 10 years is "less than we have spent on the Iraq and Afghanistan wars."

Just a week after the funeral of longtime Senate icon Senator Edward Kennedy — a life-long advocate of health care — Obama read a letter Kennedy wrote in May and asked to be read after his death.

"At stake are not just the details of policy, but fundamental principles of social justice and the character of our country," Kennedy wrote and called providing health care to all Americans "above all a moral issue."

Pundits have argued that by making universal health-care legislation his number one priority, Obama has essentially bet the farm early in his administration on an elusive goal that has been sought by every president since Theodore Roosevelt more than 100 years ago.

"I am not the first president to take up this cause," Obama said, "but I am determined to be the last."